A study on the relationship between spectral characterization and composition of plasma in laser additive manufacturing of gradient materials

Abstract

Purpose The purpose of this paper is to predict and control the composition during laser additive manufacturing, since composition control is important for parts manufactured by laser additive manufacturing. Aluminum and steel functionally graded material (FGM) were manufactured by laser metal deposition, and the composition was analyzed by means of spectral analysis simultaneously. Design/methodology/approach The laser metal deposition process was carried out on a 5 mm thick 316L plate. Spectral line intensity ratio and plasma temperature were chosen as two main spectroscopic diagnosis parameters to predict the compositional variation. Single-trace single-layer experiments and single-trace multi-layer experiments were done, respectively, to test the feasibility of the spectral diagnosis method. Findings Experiment results showed that with the composition of metal powder changing from steel to aluminum, the spectral intensity ratio of the characteristic spectral line is proportional to the elemental content in the plasma. When the composition of deposition layers changed, the characteristic spectrum line intensity ratio changed obviously. And the linear chemical composition analysis results confirmed the gradient composition variation of the additive manufacturing parts. The results verified the feasibility of composition analysis based on spectral information in the laser additive manufacturing process. Originality/value The composition content of aluminum and steel FGM was diagnosed by spectral information during laser metal deposition, and the relationship between spectral intensity and composition was established.

异质金属激光增材制造研究及应用进展（特邀）

“…(a) Schematic diagrams of the four types of joining strategies [77] ; (b) LPBF direct joining of Cu10Sn/Ti6Al4V and its interface [19] ; (c) fingercrossed 316L/CuSn10 interfacial structure and samples formed by SLM [81] ; (d) bionic SS316L/IN625 interface structure formed by LDED [82] ; (e) Ti6Al4V/SS316 stainless steel heterometal connection through the intermediate layer Cu10Sn using SLM [79] ; (f) inconel 718/Ti64 heterometal connection through VC -Inconel 718 -Ti64 combination bonding layer using LENS [80] ; (g) martensitic stainless steel/austenitic stainless steel connection through gradient layer using LENS [78] 1002304 -11 9 Influence of process parameters on the microstructure and properties of heterogeneous metal components. (a) Variation of the relative density of LMDformed GH4169/K417G heterogeneous metal components with laser power [76] ; (b) LMD parameter optimization strategy and IN625/304L heterogeneous metal components prepared under the optimal parameters [90] ; (c) Ti6Al4V/ AlSi10Mg heterogeneous metal interfaces formed by LPBF under different process parameters [30] ; (d) NiTi/CuSn10 heterogeneous metal interfaces formed by SLM under different process parameters [12] 表 6 经典异质材料体系的最优/适配工艺参数 Table 6 Optimization/processing parameters for classical heterogeneous material diagram of the integrated highspeed imaging device of the LMD equipment and highspeed imaging pictures of the Cu deposition process [99] ; (c) LDED system with integrated monitoring and sensing device [100] ; (d) (e) schematic diagram of the insitu Xray imaging device integrated into the LPBF system and the photos of the Inconel 718/316L forming process captured under different processing parameters [101] ; (f) schematic diagram of integrated optical device for LDED systems [102] 亮点文章•特邀综述 adaptive mesh and boundary conditions for thermal analysis [103] ; (b) machine learning flowchart for SLM parameter optimization [104] ; (c) simulation of powder bed temperature distribution with different gradient IN718 components during LPBF manufacturing of IN718/Ti6Al4V [105] ; (d) simulation of deformation and stress distribution in LDED manufacturing of Cu/ SS304L [83] 表 7 异质金属激光增材制造的监测技术 Table 7 Monitoring techniques for laser additive manufacturing of heterogeneous metals with or without preheating [110] ; (d) (e) comparison of microstructures of CuBe/H13 formed by LMD with or without preheating…”